A review of ecological restoration techniques in fluvial rivers

Rivers play an important role in people's living and agricultural production, however, intense human activities have broken the original ecological balance, and affected structures and functions of the river ecosystem. To restore the damaged river ecosystem back to a healthy status, effective ecological restoration measures need to be implemented. The main problems that the damaged rivers face are either the locally altered hydrological processes affected by construction of hydraulic facilities, or the deterioration of water quality resulted from pollution emissions, or both. In this study, ecological restoration techniques of the rivers affected by engineering control or pollution are reviewed respec-tively. In addition, three kinds of methods, i.e. physical, chemical and biological–ecological methods are introduced in details for the rivers affected by water pollution. At present, the development of river restoration techniques shows the following trends: 1) the scale of ecological restoration is becoming larger; 2) ecological restoration measures are required to meet multiple objectives; and 3) the man-agement of water environment is changing from water quality management to aquatic ecosystem management.     

2014年震情述评

<正>1全球地震活动概况据中国地震台网中心测定,2014年全球共发生7级以上地震13次(表1),其中包括1次8级以上地震,即2014年4月2日智利北部沿岸近海8.1级地震(图1)。2014年全球7级以上地震主要发生在环太平洋地震带,欧亚地震带活动较弱。与2013年相比,全球地震频次显著减少,能量释放略有降低。2014年全球7级以上地震活动有以下特点。     

Reviews on land use change induced effects on regional hydrological ecosystem services for integrated water resources management

This paper proposed to provide valuable information for integrated water resources management through evaluating the research on the interaction mechanism among land use changes, regional hydrological ecosystem services and human well-being. Firstly, the driving mechanism of land use and land cover changes was introduced in this paper. Secondly, the overview of the interaction mechanism among land use and land cover changes, regional hydrological ecosystem services and human well-being was given. Based on the meta-analysis, land use changes have a profound influence on regional hydrological ecosystem services, and the variation of hydrological ecosystem could benefit or impair human well-being. Finally, two suggestions were emphasized for managers or policy makers for the future integrated water resources management: (1) Proper land use makes for the water resource management; (2) Blindly pursuing the provisioning services weakens other services of hydrological ecosystem.     

中国地震标准体系进展综述

中国地震标准体系由国家标准、行业标准、地方标准、团体标准和企业标准构成.目前,我国正在实施的地震标准共计756项,其中,国家标准129项,行业标准299项,地方标准160项,团体标准23项,企业标准145项.从技术角度分类,这些地震标准可以划分为地震基本概念与规定类、地震监(观)测类、建设工程抗震设防类、地震应急救援与...     

我国花岗岩研究的回顾与展望

本文中回顾了８０年代以来国内花岗岩研究的概况。阐述了造山带花岗岩的形成和演化,次火山花岗岩的特征,Ａ－型花岗岩的成因,花岗岩形成过程中的岩浆混合作用、玄武岩浆底侵作用与花岗岩形成的联系以及花岗岩的实验岩石学研究方面的问题。展望了下一世纪花岗岩研究的某些趋向。     

膨润土颗粒混合物的堆积性质与水-力特性研究进展

膨润土颗粒混合物是高放废物深地质处置库中的一种缓冲/回填材料,掌握其堆积性质与水-力特性是开展处置库安全性能评估的关键基础。本文全面回顾和总结了近年来国内外学者对膨润土颗粒混合物的堆积性质、持水特性、结构特征、渗透特性、胀缩特性及本构模型等方面的研究进展与取得的成果,展望了几个值得进一步研究的问题。结果表明,颗粒混合物的堆积性质与粒径级配密切相关;湿化过程中,颗粒混合物由初始松散结构逐渐转变为胶结融合结构,孔隙结构逐渐趋于均一化,并伴随着颗粒破碎和错动,进而影响其水-力特性。考虑到处置库实际运营环境的复杂性,颗粒混合物的原位填充技术以及多场(热-水-力-化)耦合条件下颗粒混合物的水-力特性是今后值得深入研究的方向。     

Review of Digital Elevation Model （DEM） Based Research on China Loess Plateau

Introduction The Loess Plateau is located in the upper and middle reaches of the Yellow River, among the western Taihang Mt, eastern Riyue-Helan Mt, northern Qinling Mt, and southern Yinsan Mt (from 100°54′to 114°33′E and 33°43′to 41°31′N; Figure 1). It covers a total area of 624,000 km2. The Loess Plateau of China has drawnworldwide attention in geographical research for its unique morphological features, abundant nature resources, most serious soil erosion, as well as its pot…     

人工影响天气研究工作的回顾与展望

概述了中国科学院兰州高原大气物理研究所人工影响天气研究工作的过去与现在的发展情况。该研究工作始于１９５８年,到现在已有４０年。主要研究工作可分为三个阶段, １９５８－１９６５年为第一阶段,主要开宫山人工融雪,人工增雨及人工防雹的研究。     

2022年震情述评

<正>1全球地震活动概况据中国地震台网测定,2022年1月1日—12月31日,全球共发生6级以上地震112次,其中7级以上地震7次,最大地震为9月11日巴布亚新几内亚7.6级地震(图1)。1.1全球7级以上大震活动明显偏弱2022年全球共发生7级以上地震7次,最大地震为9月11日巴布亚新几内亚7.6级地震。全球7级以上地震强度较2021年有所降低,频次显著低于1900年以来年均20次的活动水平,且显著低于2021年(解孟雨等,2021;马亚伟等,2022),2022年全球7级以上地震频次为1900年以来最低水平(图2)。     

中国城市地震小区划实施进展及其问题讨论

城市是人口密集、财富集中的区域,也是需要采取特别抗震设防措施的重点地区。地震小区划是精细划分城市抗震设防单元的重要技术途径,可以帮助摸清城市所面临的潜在地震灾害风险,并为城市规划和建设提供更加科学的抗震设防要求。1986—2022年6月,中国共完成城市地震小区划项目369个,地震小区划总面积22856.6km²,涉及61.3%的省会城市和直辖市、33%的设区的市和地(州、盟)驻地城市以及14.1%的县(市、区、旗)所在城市。本文利用文献调研和统计学方法,系统总结了中国城市地震小区划工作开展情况,分析存在的问题,并对今后推进地震小区划工作提出了建议。